The present invention relates to therapy patches, and in particular to patches configured to apply heat or cold, along with vibration, to desired external areas of the body. “Therapy” is defined herein to include treatments to relax or otherwise provide a beneficial sensation, such as for example to treat sore muscles and the like. These devices are particularly useful for treating human muscle pain by externally applying the heat and vibration to a skin area.
A variety of electrical heating pads are known for treating muscle pain. They are typically linked to a power cord that plugs into a wall outlet. Some of these devices also incorporate a vibration system to enhance the effect of the applied heat. Where a power cord is required the device is not useful at locations where there is no nearby electrical plug. Apart from this problem, a consumer may also find it undesirable to have a linked power cord nearby. For example, if the consumer wishes to apply the pad while they sleep they may be concerned about getting tangled in the cord should they roll over.
Other types of known heating/vibratory devices use a battery to power the heater and/or vibrator. See e.g., U.S. Pat. Nos. 4,607,624, 4,979,502, 5,327,886, and U.S. Pat. No. 6,511,446. However, these devices required a large or overly expensive battery for typically desired periods of operation.
U.S. Pat. No. 5,902,256 disclosed an electrically driven vibrating massage unit. In this patent there was a heat (or cold) source that did not require a drain on the electrical power supply for the vibrating unit. Instead, heat or cold sinks were heated (or cooled) using a separate power supply, and the sinks were then inserted into the device. This system had the disadvantage of requiring a separate station for modifying the temperature of the heat or cold sinks.
There are also other known devices which have a pouch or other small structure that contains chemicals that react exothermically (upon initiation) to expel heat. See e.g. U.S. Pat. Nos. 4,925,743, 5,205,278 and U.S. Pat. No. 5,342,412. These devices can then be directed against sore tissue or muscle as desired by the user, or even more typically be inserted into a glove or boot to provide prolonged protection from extreme cold conditions. However, these devices did not address the desirability of associating a portable vibratory system with the heating source, much less solve the weight and power concerns that such a structure would have.
In connection with designing devices of this type, apart from the problems noted above, there are additional problems with ensuring that the vibration that is produced by the device is used in an efficient manner that extends to the full contact surface of the device. Some known devices have regions of high vibration and other portions of their contact surface with insufficient vibration. This problem makes such devices difficult to design as the size of the contact surface grows.
Thus, it can be seen that a need exists for improved, lightweight, inexpensive, self-contained vibrating heating/cooling pads.